2/9+4/7:9/28

To add fractions, we need to have a common denominator. In this case, the least common denominator is 63.

So, we need to rewrite the fractions with a denominator of 63:

2/9 = 14/63 (multiply the numerator and denominator by 7) 4/7 = 36/63 (multiply the numerator and denominator by 9) 9/28 = 99/79 = 81/63

Now, the expression becomes:

14/63 + 36/63 - 81/63

Adding the numerators together, we get:

(14 + 36 - 81) / 63 = -31 / 63

Therefore, 2/9 + 4/7 - 9/28 = -31/63.